Wrapping machines

ABSTRACT

Article-feeding mechanism which advances a procession of articles continuously towards a positioning stop and includes reciprocating leading and trailing grippers, and means for closing these grippers to engage respectively the leading and the next article in the procession after the leading article has contacted the stop, then advancing the grippers to feed the articles forward, the leading gripper imparting a larger forward movement to the leading article than is imparted to the next article by the trailing gripper, then opening the grippers to release the articles with a space between them and finally returning the grippers.

United States Patent Inventors Appl. No.

Filed Patented Assignee Priority Matthew Parker Leeds;

Edwin Hall Lazenby, Bardsey, near Leeds, both 01, England Feb. 4, 1969June 22, 1971 Rose Forgrove Limited Leeds, England Feb. 6, 1968 GreatBritain 5835/68 WRAPPING MACHINES 5 Claims, 6 Drawing Figs.

US. Cl......

Int. Cl

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mss 25/04 Field of Search;

[56] References Cited UNITED STATES PATENTS 3,262,541 7/1966 De Gain198/19 Primary Examiner-Richard E. Aegerter Attorney-Wats0n, Cole,Grindle & Watson ABSTRACT: Article-feeding mechanism which advances aprocession of articles continuously towards a positioning stop andincludes reciprocating leading and trailing grippers, and means forclosing these grippers to engage respectively the leading and the nextarticle in the procession after the leading articlehas contacted thestop, then advancing the grippers to feed the articles forward, theleading gripper imparting a larger forward movement to the leadingarticle than is imparted to the next article by the trailing gripper,then opening the grippers to release the articles with a space betweenthem and finally returning the grippers.

BQSSBJST PATENTED JUN22 I9?! SHEET 1 OF 4 v wi #TTOf/MEKS waarsusoMscrrrsias It is often necessary when feeding articles to be wrappedinto a wrapping machine to space them apart from each other, forexample, when they are of irregular shape and would tend to overlap orinterlock and so impede the feed.

The invention provides a feeding mechanism for achieving such spacing ofthe articles automatically.

The invention provides apparatus for feeding articles to a wrappingmachine comprising feed mechanism for advancing a procession of articlescontinuously towards a positioning stop, reciprocating leading andtrailing grippers, and means for closing these grippers to engagerespectively the leading and the next article in the procession afterthe leading article has contacted the stop, then advancing the grippersto feed the articled forward, the leading gripper imparting a largerforward movement to the leading article than is imparted to the nextarticle by the trailing gripper, then opening the grippers to releasethe articles with a space between them and finally returning thegrippers.

If desired, the leading gripper may have a pushing face which, on itsnext closing movement upon the second article, engages the leadingarticle to advance it to a disposal position. Alternatively the leadingarticle may be removed from the procession at the position to which itis advanced by the aforesaid forward movement. I

The leading article may be fed directly into the wrapping machine fromeither of said positions, e.g. by a prong on a chain conveyor running atright angles to the direction of advance of the feed mechanism. However,once the leading article has been separated from the others it can bedisposed of and conveyed to the wrapping machine in any desired way.

Preferably the stop remains in the path of the articles and preventsgripper closure if no article is in the correct position to be gripped.This ensures that the positions of articles placed at random in theprocession are later corrected, so that feeding, especially whenstarting up, is simplified.

The invention is particularly suitable for the feeding of chocolate barsof irregular outline. During normal running, all the chocolate bars inthe feed channel leading to the stop, except that in the leadinggripper, may move at an average speed very little more than the width ofa bar per cycle, the period of arrest of the bars by the stop being onlyjust enough to ensure that the leading bar is correctly positioned. Theadvantage of this very short dwell is that scuffing of the undersides ofthe chocolate bars is minimized.

Having determined that the leading chocolate bar is in position, thestop quickly moves clear to allow passage of the bar and then returns,behind the leading bar and in front of the second bar, i.e. into the gaplater entered by the pushing face of the leading gripper upon its returnand closure; and is so timed that it will safely limit the movement ofthe bars in the feed channel when the grippers are open.

The function of the trailing gripper is to prevent displacement of acorrectly positioned second bar during movement away from it of theleading bar, so that the gap between the bars is always as intended,both in amount an position. As the stop is inoperative at this time theoperator could, but for the trailing gripper, when pushing bars alongthe feed channel to catch up with those already feeding upset thecorrect positioning and cause the stop and pushing face to collide witha chocolate bar occupying the space into which they should return. Thus,wrong positioning of the bars is always prevented, for if the operatorpushes them when the grippers are open, this can only advance theirarrival at the stop, and result in a momentary excess of skid as thefeed member slides ineffectively under them.

A constantly moving belt may constitute the feed mechanism, but weprefer to use a system of bars, as described later, arranged to give asomewhat similar action to that of the well-known cakewalk" motion.

These feed bars are capable of emptying the feed channel of chocolatebars, whereas the dead plate needed to support the chocolate barsimmediately the belt begins to round the pulley, if a feed belt is used,invariably holds back several of the bars and so reduces feeding space.Also, stainless steel bars are much easier to keep clean than is a belt.

One embodiment of the invention is illustrated in the accompanyingdrawings, in which: a

. FIG. 1 is a side elevation of mechanism for feeding chocolate bars toa wrapping machine with the front plate removed,

FIG. 2 is a plan view partly broken away,

FIG. 3 is an end elevation,

FIG. 4 is a section on the line IV-IV in FIG. 1,

FIG. 5 is an enlarged view of a trip mechanism looking in the directionof the arrow X in FIG. 1, and

FIG. 6 is a corresponding plan view.

As shown in the drawings articles, in the case illustrated chocolatebars 100, are placed manually in a feed channel constituted by threefeed bars I, 2, and 3 and side guides 4, 5 supported on plates 104, I05,the articles extending transversely to the feed bars as shown in FIG. 3.The outer feed bars 1 and 3 perform a substantially horizontalreciprocating movement while the center feed bar performs a cakewalkmotion, receiving both a horizontal and a vertical reciprocatingmovement.

The center bar 2 receives a substantially horizontal movement from a cam6 (FIG. 4) through the agency of a cam lever 7, a link 8, and a lever 9(FIG. 1), which oscillates levers 10 fixed to a rear shaft 11 andpivoted by pins 12 to a bracket 14 on a support 13. Similar levers l0and a similar bracket 14 are provided near the front of the support 13,the levers 10 being fixed to a shaft IS. The front and rear pins 12carry levers 17, 16 respectively, which are joined by a link 18; thelevers l7, 16 being oscillated by a cam 19 (FIG. 4), through the agencyof levers 20, 21, pivoted respectively to the shafts 15 and 11, andlinks 22, 23 thereby imparting a small vertical movement to the centerbar 2, which is fixed to brackets 24, 25 on the levers l6, 17.

The bars 1 and 3 are given a substantially horizontal movement only froma cam 26 (FIG. 4) through the agency of a lever 27 and a carrier 28having three pillars 29, one fixed to the bar 1 and the others to thebar 3. The rear ends of the bars 1 and 3 are supported by pillars 30 onbrackets 31, 32 pivoted to a lever 33 which rocks on a shaft 34.

Apart from small increments at the beginning and end of the leftwardmovement of bars 1, 2, and 3 for acceleration and deceleration, themotion is at uniform speed, and the distance moved by each bar at thisspeed is just over half the width of a chocolate bar. The bars 1 and 3begin to decelerate near the end of their leftward movement at themoment when the bar 2, having just accelerated up to speed from thebeginning of its leftward movement, comes level with bars 1 and 3, afterlifting about one-sixteenth inch. This upward motion continues for aboutanother one-sixteenth inch, so that the articles previously beingcarried leftward by the bars 1 and 3 now continue, still at the sameunifonn speed, to move leftward on the bar 2, and the bars 1 and 3return below the articles. The bar 2 begins to decelerate, near the endof its leftward movement and halfway through its total downwardmovement, and at this moment the bars l and 3 have just accelerated upto speed from the beginning of their leftward movement, so that againthe articles continue to move uniformly leftward, having transferredback to the bars I and 3, the bar 2 meanwhile returning below thearticles.

The conjoint cakewalk motion of the bar 2 and horizontal reciprocatingmotions of the bars 1 and 3 are thus effective to impart a continuousfeed to the articles 100, moving them in procession towards apositioning stop 53.

The articles in the procession are engaged in pairs by leading andtrailing grippers, which close on the first two articles in theprocession after the leading article has contacted the stop 53. Thesegrippers then advance the first two articles by different amounts toprovide a definite spacing between them, release the articles, return,and afterwards again grip a pair of articles.

The trailing gripper is constituted by a gripper jaw 36 pivoted by astud 35 to be support 13 so that the jaw 36 partakes of the horizontalmovement of the center bar 2 which acts as a cooperating lower gripperwhen a lever 37, pivoted on the shaft 115 and having a runner 137coacting with a cam 38, is permitted by the cam 33 to descend under theaction of a spring 63 and so to cause a cam piece 39 on the lever 37 toallow a runner 40 on the jaw 36 to descend under the action of a spring431, to close the jaw 36 on the article 1008 behind the leading articleNBA on the feed bars 1-3 just after the center bar 2 has begun to liftall the articles from the bars 1 and 3. At the moment it is gripped thearticle 100B is correctly positioned, i.e. touching the leading article100A which is now in contact with the stop 53 and gripped by the jaws42, 43 of the leading gripper 101. The jaws d2, 43 are mounted on pivotpins 47, 48 on a lever 45 pivoted on a shaft 46 and are interconnectedby meshing gear segments M3, 144. The leading gripper 101 is operated bythe cam 6 and the lever 7 through a link 44 and the lever 45, andopening and closing movement of the jaws 42, 43 is controlled by a campiece 49 on the lever 37, a runner 50 on the jaw 42 and a spring 51connected between the jaws.

As they are both operated by the cam 6 the leading and trailing grippersmove together, but the lever ratios are such that the leading gripper iscaused to move a greater distance than the other, so that on arrival atthe extreme leftward position, as shown in HO. 1, the leading article100A and the immediately following article 1098 are an appreciabledistance apart and the lever 37 has lifted to its uppermost position,causing the jaws 36, 42, and 43 to open and thus release the leadingarticle 100A on to a platform 52, which is cut away for the entry of thejaw 42 and also to free the next article 1008,

. which cannot however be displaced to an unsafe position because thestop 53, which is pivoted to the lever 37 at 54, is interposed betweenit and the leading article 100A.

As the grippers and the center bar 2 return, the article 1008 is movedby the feed. bars l and 3 up to the stop 53, leaving sufficient room foran upstanding pushing face 142 on the jaw 42 to rim, after retraction ofthe grippers by the center bar 2, into the space 102 between the article1008 and the leading article 100A as the grippers close, the pushingface 142 preventing unsafe displacement of the article 1008 untilclosure is completed and while the stop 53 descends well below the feedlevel.

It is evident that a third article will now be held by the gripper 36and is thus restrained from following the article 1003 except at theprescribed rate.

The leading article 100A is pushed from the platform 52 to position 55by the upstanding face 142 on the jaw 42 upon the next leftward movementof the closed grippers, from which position it will normally be movedinto the wrapping machine by a prong 56 on a chain conveyor. A lightspring 57 holds a trip pin 58 (F I08. and 6) against a stop 59 andoverlapping a trip wedge 60 to prevent downward movement of the lever 37under the pull of the spring 63 unless an article overcomes the spring57 by pressing against the stop 53, to which is fixed an arm 61 carryingthe pin 58. Movement of the pin 58 to the right as seen in FIG. 1 islimited by an angle piece 62 which forms with the trip wedge 60 achannel for controlling the pin 58 and the stop 53 during movement ofthe lever 37. The stop 53 thus always obstructs the feed channel and thegrippers stay open unless an article trips the stop.

It is not essential that the articles should be moved at uniform speedalong the feed channel, and the bars 1 and 3 need not move the articlesthrough exactly the same distance as the bar 2. Chocolate bars havingirregular bases, e.g. bars containing projecting nuts, may require thebars l and 3 to have-vertical movement as well as the bar 2 to ensureclearing the projections during the return of the bars.

The above-described apparatus can also be used to feed groups ofarticles, which tends to be uneconomical when performed by hand becauseof the concentration required over long periods to ensure that thecorrectnumber of articles per group I8 assembled and placed in the mfeedof the wrapping machine and extra feeders may be needed to keep up withthe speed of the machine. If the articles referred to above as secondand third" articled are considered themselves each to consist of two ormore chocolate bars, the ready adaptation to group feeding can beappreciated, e.g. if the apparatus is set up to feed single 1 inch widebars, then a wide bars will be fed by it in groups of four, the onlyspecial conditions being that the leading gripper must safely hold allof the first four bars, and that the trailing gripper must safely holdat least the foremost one of the following bars.

When the apparatus is used to feed groups of chocolate bars, it is moreconvenient to move the articles directly into the wrapping machine fromposition A instead of from position 100, e.g. by conveyor prongs similarto those indicated at 56. In this case no pushing face M2 is required onthe jaw 42.

The apparatus may also be used to count articles, e.g. by inserting apusher after every n cycles of gripper closure into the gap left by thepushing face M2 on the jaw 62, after gripper opening, so that groups ofN objects can be pushed clear in an identifiable manner. This is oftenuseful, e.g. to deal with wrapped objects being discharged from awrapping machine.

What we claim as our invention and desire to secure by Letters Patentis:

1. Apparatus for feeding articles to a wrapping machine comprising feedmechanism for advancing a procession of articles continuously towards apositioning stop, reciprocating leading and trailing grippers, andgripper-actuating means operatively associated with said grippers andeffective first to close the grippers so that they engage respectivelythe leading and the next article in the procession after the leadingarticle has contacted the stop, to advance the grippers to feed thearticles forward, the leading gripper imparting a larger forwardmovement to the leading article than is imparted to the next article bythe trailing gripper, then to open the grippers to release the articleswith a space between them and finally to return the grippers.

2. Apparatus as claimed in claim 1, in which the leading gripper has apushing face which, on its next closing movement upon the secondarticle, engages the leading article to advance it to a disposalposition.

3. Apparatus as claimed in claim 1 which includes a trip mechanism forpreventing closure of the grippers unless an article is in contact withthe stop.

4. Apparatus as claimed in claim 3, which includes a spring loaded levermovable under the control of a cam to permit of closing of the grippers,and a stop pin attached to the stop and biased to a position to preventsuch movement of the lever, the stop being pivoted to the lever andmovable by pressure of an article to overcome the bias and free thelever for movement to cause closure of the jaws.

5. Apparatus as claimed in claim 1, in which the feed mechanismcomprises a first feed bar which performs a cakewalk motion and a pairof feed bars which reciprocate in a substantially horizontal directionand feed the articles forward while the first feed bar is in a loweredposition and performing a return stroke.

1. Apparatus for feeding articles to a wrapping machine comprising feedmechanism for advancing a procession of articles continuously towards apositioning stop, reciprocating leading and trailing grippers, andgripper-actuating means operatively associated with said grippers andeffective first to close the grippers so that they engage respectivelythe leading and the next article in the procession after the leadingarticle has contacted the stop, to advance the grippers to feed thearticles forward, the leading gripper imparting a larger forwardmovement to the leading article than is imparted to the next article bythe trailing gripper, then to open the grippers to release the articleswith a space between them and finally to return the grippers. 2.Apparatus as claimed in claim 1, in which the leading gripper has apushing facE which, on its next closing movement upon the secondarticle, engages the leading article to advance it to a disposalposition.
 3. Apparatus as claimed in claim 1 which includes a tripmechanism for preventing closure of the grippers unless an article is incontact with the stop.
 4. Apparatus as claimed in claim 3, whichincludes a spring loaded lever movable under the control of a cam topermit of closing of the grippers, and a stop pin attached to the stopand biased to a position to prevent such movement of the lever, the stopbeing pivoted to the lever and movable by pressure of an article toovercome the bias and free the lever for movement to cause closure ofthe jaws.
 5. Apparatus as claimed in claim 1, in which the feedmechanism comprises a first feed bar which performs a cakewalk motionand a pair of feed bars which reciprocate in a substantially horizontaldirection and feed the articles forward while the first feed bar is in alowered position and performing a return stroke.